SARS-CoV-2 S protein RBD (K417N, E484K, N501Y), His Tag (SPD-C52Hp) is expressed from human 293 cells (HEK293). It contains AA Arg 319 - Lys 537 (Accession # QHD43416.1 (K417N, E484K, N501Y)). The K417N / E484K / N501Y mutations were identified in the SARS-CoV-2 Beta variant (Pango lineage: B.1.351; other names: 20H/501Y.V2).